JP2003272954A - Method of manufacturing solid electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the quality of a solid electrolyte which is used for a solid electrolytic capacitor and formed of an electrolytic polymer film so as to improve the solid electrolytic capacitor in ESR characteristics. <P>SOLUTION: When an electrolytic polymer film as a second solid electrolyte is formed on the surface of a first solid electrolytic layer formed of a conductive polymer of an inorganic semiconductor film or a chemical polymer film, a feeding terminal having a prescribed resistance or a part of a feeding wiring circuit anode with a prescribed resistance is arranged apart from the first solid electrolytic layer to feed an electric power, so that the surface (dielectric layer, inorganic semiconductor film, chemical polymer film or the like) of the pellet is hardly damaged by the feeding terminal because the feeding terminal is hardly brought into contact with the pellet. Integrating currents become nearly equal to each other in amount through the pellets, and the electrolytic polymer films are uniformly formed through the pellets, so that the solid electrolytic capacitors which each have a low ESR, uniform and stable qualities, and is superior in productivity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solid electrolytic capacitor, and more particularly to a method for manufacturing a solid electrolytic capacitor which forms an electropolymerized film of a conductive polymer as a solid electrolyte.

[0002]

2. Description of the Related Art A conventional method for manufacturing a solid electrolytic capacitor will be described. Step of forming porous anode body: First, a valve-action metal powder such as Ta is mixed with a binder for enhancing the moldability to prepare a granulated powder for press molding. Next, using this granulated powder, a compression molded body in which an anode lead (valve metal such as Ta is used) is embedded is prepared by a pressing method. This molded body was heated at a high temperature of about 1300 to 1600 ° C. for 10 −6 Torr.
A porous anode body for a solid electrolytic capacitor is obtained by sintering in a high vacuum of about r. Hereinafter, the anode body obtained by subjecting the anode body to various treatments is referred to as a pellet.

Formation of Dielectric Layer: Next, an oxide layer as a dielectric layer is formed on the surface of the above-mentioned porous anode body by a method called anodic oxidation. In anodic oxidation, the porous anode body and the counter electrode for energization are immersed in an electrolyte solution, and the porous anode body is used as an anode and the counter electrode is energized to form an oxide layer on the surface of the porous anode body. .
The potential difference between the porous anode body and the counter electrode at this time is called the formation voltage. By controlling this formation voltage, the thickness of the oxide layer is controlled.

Solid electrolyte layer forming step (inorganic semiconductor film or chemically polymerized film forming step) and solid electrolyte layer forming step
(Formation of electrolytically polymerized film); Next, the above-mentioned dielectric layer (oxide layer)
By forming a conductive material film as a counter electrode surface corresponding to the anode metal on the surface of, a basic structure as a capacitor can be obtained. As the conductive material film, a manganese dioxide layer called a solid electrolyte layer obtained by thermally decomposing manganese nitrate is generally used, but recently, a conductive organic polymer such as polypyrrole is chemically polymerized by chemical polymerization. Then, a film having an electrolytic polymerized film formed on the surface thereof by electrolytic polymerization has also come to be used.

Since this conductive polymer has a lower resistance than manganese dioxide, the equivalent series resistance (ESR) of the capacitor is high.
Has a merit that the element can hardly smoke or ignite because the insulating reaction to heat is quick.

Means for forming a conductive polymer film are roughly classified into chemical polymerization, which is formed only by a chemical reaction by a chemical,
There are two types of electrolytic polymerization in which electrodes are electrochemically formed by bringing electrodes into close proximity or contact with each other. However, since electrolytic polymerization cannot form a polymerized film on a dielectric layer that is electrically insulating, a manganese dioxide layer of an inorganic semiconductor film or a chemically polymerized film of a conductive polymer film must be prepared before applying electrolytic polymerization. It is necessary to form a conductive layer such as the above as a base on the dielectric layer.
Further, at the time of electrolytic polymerization, it is necessary to bring a power supply terminal for energization close to or in contact with the polymer film forming portion.

As described above, the electrolytic polymerization has a more complicated process than the chemical polymerization, but it has the advantages that the polymer film produced has a low resistance and that the layer can be formed thick in a short time. It is used as one of the leading methods for forming a conductive polymer film.

Re-formation step: Next, the pellets on which the solid electrolyte layer formed as described above is re-formed in a chemical conversion solution such as a phosphoric acid solution by a method substantially similar to the method used in the anodic oxidation described above. Apply voltage.

The voltage applied at this time is set to be equal to or lower than the value applied during the previous anodic oxidation. This process is called re-formation, and by performing this re-formation, minor defects caused by mechanical / chemical stress at the time of forming the solid electrolyte layer are repaired, and the quality of the capacitor is further stabilized.

Step of forming cathode layer: Next, a cathode layer of a conductive material film such as graphite paste or silver paste is formed on the re-formed pellets. The cathode layer connects the solid electrolyte layer and the external terminal (cathode) for mounting, and also has the functions of reducing the connection resistance and relieving stress when the capacitor is packaged and mounted.

External terminal / exterior step: Finally, an external terminal made of metal for mounting is added to the element after the cathode is formed by welding, adhesion, etc., and further epoxy resin is used for the purpose of improving moisture resistance and handling. A solid electrolytic capacitor is obtained by coating with resin or the like.

[0012]

When carrying out electrolytic polymerization, a power supply terminal for supplying power is required, and this power supply terminal is required to have low electrochemical reactivity. Therefore, a metal such as platinum or SUS is usually used. Material is used. However, since they are usually hard materials, the dielectric layer and the underlying conductor layer (chemically polymerized film, etc.) are easily destroyed when they come into contact with the pellets during electrolytic polymerization.

When destroyed, a large current flows from the destroyed portion in the re-formation in the next step, and the conductive polymer around it is insulated. As a result, the conductive polymer film has a high resistance as a whole and deteriorates the ESR characteristic of the capacitor. In order to avoid this problem, it is most effective not to contact the power supply terminal with the pellet, but if the power supply terminal is too far from the pellet, the electrolytically polymerized film (hereinafter referred to as the electrolytically polymerized lead part) extending from the power supply terminal will be pelletized. And the electrolytic polymerized film on the pellet cannot be formed. For this reason,
The distance (gap) between this pellet and the power supply terminal is 0.1 mm
It is necessary to control with the following accuracy. The accuracy of this distance control is relatively easy when the pellets are processed one by one.

However, it becomes very difficult to process a large number of pellets simultaneously as shown in FIGS. 8 (a) to 8 (d). That is, FIG. 8 is a schematic view for explaining molding of an electrolytically polymerized film in a conventional method for manufacturing a solid electrolytic capacitor,
After obtaining the above-mentioned porous anode body, as a preparatory work from the step of forming the dielectric layer to the step of forming the cathode layer, in order to simultaneously process a large number of pellets 3, as shown in FIG. The pellets 3 of the positive electrode body are welded and joined to the first rectangular holder 4 (for example, aluminum, titanium, etc.) at a predetermined interval in a suspended state, and the steps from the dielectric layer forming step to the cathode layer forming step are performed. In the forming step of the solid electrolyte layer in this forming step (after forming the inorganic semiconductor film or the chemically polymerized film, in forming the electrolytic polymerized film, as shown in FIG. 21 (for example, a highly conductive metal plate such as aluminum) by welding or the like at a predetermined interval, and the pellet 3 of FIG. 8 (c) is enlarged. A space S is provided between them, and they are arranged close to each other, as shown in FIG.
Power is supplied by a DC power source 25 connected between the counter electrode 13 (cathode side) and the first rectangular holder 4 (anode side) shown in (d), but when the electrolytic polymerization film 9 is formed, It will be very difficult.

The reason for this difficulty is that the anode lead 1 from the pellet 3 is easily bent, and it is difficult to make the length of the power supply terminal 20 uniform, and so on. Because it comes. Industrially, the work efficiency is very poor and it is not practical unless the method of treating a large number of pellets 3 at a time in a suspended state by the fourth rectangular holder 4 as shown in FIG. As shown in (d), a large number of pellets 3 as shown in FIG. 8 are simultaneously treated by allowing the defective formation of the electropolymerized film 9 to some extent. Further, since the chemically polymerized film formed as a base on the pellet 3 is not completely uniform in each pellet, the distance between the pellet 3 and the power supply terminal 20 in FIG. 8 can be made the same for all the pellets. In this case, however, the electrolytically polymerized film 23 will have many variations such as over-formed products 23a and under-formed products 23b or unformed products.

The reason why this variation occurs is that the distance between the feed terminal for electrolytic polymerization and the pellet is not constant, and the state of the chemically polymerized film formed as a base on the pellet is different for each pellet. First, the variation between the power supply terminal and the pellet makes the time required for the electrolytic polymerization lead portion to reach the pellet uneven. Since the formation of the electropolymerized film on the pellets starts from the time when the solid electrolytically polymerized lead parts come into contact with the pellets, if the electropolymerization time is kept constant, the electropolymerized film on the pellets that the lead parts come into contact with earlier will be thicker. If the pellets are over-formed (over-formed article 23a) and contact is delayed, they become thin (under-formed article 23b) or unformed. Next, regarding the variation in the formation of the underlying chemically polymerized film,
This affects the rate of formation of the electropolymerized film after the electropolymerized lead portion comes into contact with the pellet. That is, when the conductivity of the base is high and the coating area is large, the electrolytically polymerized film is formed more quickly. Also in this case, if the electrolytic polymerization time is kept constant, the state of formation of the polymerization layer of each pellet varies. In any of the above cases, the formation can be made uniform by conducting the polymerization while monitoring the formation state of the electropolymerized film of each pellet, but such a method is complicated and cannot be used as a production method for mass production.

As described above, electrolytic polymerization is effective as a method for obtaining a high-quality polymer film, but it is difficult to use it as a mass production method because it is apt to damage pellets during power supply or the power supply system becomes complicated. Had.

A method of processing by providing a gap S between the power supply terminal 20 and the pellet 3 described above (method of processing without contact)
On the other hand, as a method for treating the power supply terminal 22 having a contact surface with the pellet 3 by contact, for example, Japanese Patent Laid-Open No. 05-28
Japanese Patent No. 3289 discloses a power supply made of stainless steel or platinum that is brought into contact with a pellet to prevent damage to the pellet when electrolytically polymerizing an electropolymerized film 24 of a conductive polymer on the pellet 3 as shown in FIG. Contact surface 22a of terminal 22
Although a technique of making the structure of U-shaped or spherical has been disclosed, there is a problem that the generation of flaws in the pellet cannot be completely prevented because the power supply terminal 22 is hard.

In order to solve this problem, for example, in Japanese Unexamined Patent Publication No. 2001-102257, as shown in FIG. 13, a soft power feeding terminal 24 (for example, a conductive material) is used as a power feeding terminal for forming an electrolytic polymerized film 9. A technique is disclosed in which rubber) is used in contact with the pellet 3 to reduce damage to the dielectric layer 5 and the chemical polymerization film 7 due to the power supply terminal 24 and prevent the electrolytic polymerization film 23 from being insulated in the re-forming step. However, the formation of the electropolymerized film 23 becomes insufficient at the contact point of the power supply terminal 24, and there is a problem that the characteristics, quality, etc. are affected unless this section is repaired.

An object of the present invention relates to a power supply for electrolytically polymerizing a conductive polymer film on a pellet, and makes the formation of the electrolytically polymerized film uniform to reduce the ESR characteristics and variations of the solid electrolytic capacitor. Another object of the present invention is to provide a method for manufacturing a solid electrolytic capacitor which has a simple power feeding method and is excellent in mass productivity.

[0021]

A method for manufacturing a solid electrolytic capacitor according to claim 1, 2 or 3 according to the first invention of the present application, which is provided for solving the above-mentioned problems, comprises a method of sintering a valve metal powder. The body is a porous anode body, and a dielectric layer, a first solid electrolyte layer made of a conductive polymer of an inorganic semiconductor film or a chemically polymerized film, and a second layer made of a conductive polymer film of an electrolytic polymerized film on the surface of the body. After sequentially forming a solid electrolyte layer and a cathode layer, and then connecting external terminals to the porous anode body and the cathode layer,
In a method of manufacturing a solid electrolytic capacitor manufactured by coating with a resin, the power supply for forming the electrolytically polymerized film is performed by disposing a power supply terminal having a predetermined resistance in the first solid electrolyte layer. To do. Further, it is characterized in that power supply for forming the electrolytically polymerized film is performed by using a predetermined resistor in a part of the power supply wiring circuit anode side other than the power supply terminal.
Also, the value of the resistance used for the power supply terminal and a part of the power supply wiring circuit anode side other than the power supply terminal is 10Ω to 1000Ω.
Is characterized in that.

By adopting such a manufacturing method, when forming the electrolytic polymerized film, the power supply for forming the electrolytic polymerized film is
Since the chemical polymerization film is formed by using a predetermined resistance on a part of the power supply terminal having a predetermined resistance or the power supply wiring circuit anode other than the power supply terminal, the power supply terminals are not in contact with each other. Therefore, the pellet surface (dielectric layer) is not damaged. Further, the integrated current amount between the pellets becomes almost uniform, and the formation of the electropolymerized film between the pellets becomes uniform,
There is an advantageous effect that it is possible to manufacture a solid electrolytic capacitor having stable ESR (equivalent series resistance) and variation of the solid electrolytic capacitor with stable quality.

A method for manufacturing a solid electrolytic capacitor according to a second invention of the present application, which is provided for solving the above-mentioned problems, is the method for manufacturing a solid electrolytic capacitor according to claim 4, wherein a plurality of the porous anode bodies are provided. Connected to the holder, and a plurality of power supply terminals having the predetermined resistance are connected to a second holder having conductivity to be formed, and the connected power supply terminals are connected to the first solid of the porous anode body. It is characterized in that they are arranged separately from each other in the electrolyte layer and power is supplied to form the electrolytic polymerized film for each unit of the second holder.

By adopting such a manufacturing method, the integrated current amount between the pellets becomes substantially uniform, the formation of the electrolytically polymerized film between the pellets becomes uniform, and the power feeding method is simple and the mass production method is easy to adopt and the production efficiency is high. improves.

A method for manufacturing a solid electrolytic capacitor according to a third aspect of the present invention, which is provided for solving the above-mentioned problems, is the method for manufacturing a solid electrolytic capacitor according to claim 5, wherein a plurality of the porous anode bodies are provided. Connected to the holder, several power supply terminals are connected to a third holder having conductivity, and one predetermined resistor is connected to each third holder to form the connected power supply terminals. The first solid electrolyte layer of the connected porous anode body is arranged separately from each other, and power is supplied to each of the third holder units to form the electropolymerized film through the connected resistor. And

By adopting such a manufacturing method, the third
Although it is not possible to suppress the variation in the formation of the electropolymerized film of several pellets in the holder of the above, it is possible to suppress the variation that is more acceptable than the conventional manufacturing method described above, and the structure of the power supply terminal part is simple and the production efficiency is high. Is improved.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 (a) to 1 (d) are schematic views for explaining the formation of an electrolytically polymerized film in the method for producing a solid electrolytic capacitor according to the first and second embodiments of the present invention. FIG. 2 is an enlarged view of the positional relationship between the power feed terminal with resistance and the pellet of FIG. 1 (c) of the present invention. FIG. 3 is a diagram of the present invention.
FIG. 3D is a partially enlarged view of the pellet after the formation of the electropolymerized film of (d). FIG. 4 is an enlarged view in which a power feeding terminal with resistance is joined to the second holder of FIG. 1 (a) of the present invention. FIG. 5 is a schematic correlation diagram of the tip potential of the electrolytic polymerization film, the electrolytic polymerization current, and the integrated value of the electrolytic polymerization current with respect to the electrolytic polymerization time of the present invention. FIG. 6 is a state diagram after formation of the electropolymerized film of the present invention. FIG. 7 is a block-type resistor-containing power supply terminal diagram for supplying power via a resistor for each third holder unit in the method for manufacturing a solid electrolytic capacitor according to the third embodiment of the present invention.

Step of forming porous anode body: The method of forming the porous anode body is the same as the conventional manufacturing method. The valve metal Ta powder used in the present invention has an average particle size of 10 μm and a binder addition amount of 5 wt%.
Powder a was prepared, and a molded body in which the anode lead 1 was embedded was prepared by a pressing method. This molded body is 10 −6 Torr
The porous anode body 2 for a solid electrolytic capacitor was obtained by sintering at 1600 ° C. for 30 minutes in the following vacuum or inert gas atmosphere. (Hereinafter, this porous anode body and one obtained by subjecting it to various treatments are referred to as pellet 3).

After obtaining the porous anode body 2 in the above-mentioned porous anode body forming step, a large number of pellets 3 are simultaneously treated as a preparatory work from the subsequent dielectric layer forming step to cathode layer forming step. In order to do so, as shown in FIG. 1 (a), the pellets 3 of the porous anode body 2 are placed in a first rectangular holder 4 having conductivity such as aluminum or titanium at regular intervals according to the size of the pellets. The holders 4 are joined by welding or the like in a suspended state, and the holders 4 are set in a batch jig (not shown) at desired intervals.

Step of forming a dielectric layer: Using the batch jig in which a large number of pellets 3 of the porous anode body 2 are joined to a first rectangular holder 4 in a suspended state and set.
The formation of the dielectric layer 5 (for example, Ta2O5 layer) is performed by anodic oxidation in the same manner as in the manufacturing method described above because the dielectric layer 5 is formed on the surface and inside the porous anode body. To form. At this time, the chemical conversion voltage was 18 V and the chemical conversion liquid was a 0.6% phosphoric acid aqueous solution.

Solid Electrolyte Layer Forming Step; (Formation of Chemically Polymerized Film) The formation of the first solid electrolyte layer 8 made of a conductive polymer of the chemically polymerized film 7 is carried out in the same manner as in the conventional manufacturing method. After the formation of the layer 5, as shown in FIG. 3 in the form of FIG. 1 (b), the first solid of the conductive polymer of the inorganic semiconductor film 6 or the chemically polymerized film 7 is formed on the dielectric layer 5 of the pellet 3. The electrolyte layer 8 is formed. First, a chemical polymerization film 7 made of a conductive polymer is formed on the pellet 3 by chemical polymerization, and this film serves as a base for the next electrolytic polymerization. At this time, a 60% iron dodecylbenzenesulfonate (Fe.DBS) methanol solution was used as the oxidant solution, and the pellets were immersed therein for 5 minutes and then dried. Then, an aqueous solution in which pyrrole was dissolved by 5% was used as a polymerization liquid, and the pellet 3 was immersed therein for 20 minutes and then dried. Then, the pellet 3 is washed with methanol to remove residual unreacted substances and by-products that do not contribute to the conductivity to form the chemical polymerization film 7, and the pellet 3 for carrying out the electrolytic polymerization (see FIG. 1 (b ), Refer to the holder with pellets)).

Solid Electrolyte Layer Forming Step: (Formation of Electropolymerized Membrane) Electrolysis of the second solid electrolyte layer in a form in which a plurality of pellets 3 are connected to the first rectangular holder 4 at regular intervals. The method of forming the polymerized film 9 is as follows.
The second rectangular holder 10 having conductivity is immersed as shown in FIG. 1 (b), and has conductivity as shown in FIG.
A plurality of resistance-containing power supply terminals 11 joined at regular intervals (for example, stainless steel or aluminum) are provided with a resistance of 20Ω. The range of this resistance value is preferably 10 Ω to 1000 Ω, and if it is less than 10 Ω, the control of polymerization becomes difficult and the dispersion of the electropolymerized film becomes large, and if it exceeds 1000 Ω, the polymerization voltage becomes high and the pellet has a characteristic adverse effect (eg, , Deterioration of LC characteristics, etc., and also safety in work becomes a problem. This resistor-containing power supply terminal 11 is shown in FIG. 1 (c) and an enlarged view with a gap S of 0.1 mm or less on the upper part of the pellet of the chemically polymerized film 7 on which the first solid electrolyte layer 8 made of a conductive polymer is formed. As shown in FIG. 2, the first solid electrolyte layer 8 is spaced apart from each other, and is disposed between the counter electrode 13 (− pole) and the first rectangular holder 4 (+ pole) shown in FIG. 1 (d). Electric power is supplied by the constant current DC power source 17 arranged. This power supply is performed through the power supply terminal 11 by setting the power supply current so that the current per pellet is 5 mA (for example, when electrolytic polymerization is performed on 10 p at a time, the energization amount is set to 5).
0 mA). As a method of incorporating the resistor 12 into the power supply terminal 11, for example, the lead portion of a commercially available resistor with a lead terminal is replaced with a material having strong oxidation resistance such as SUS. In this state, the counter electrode 13 (-
(Pole) and a second rectangular holder 10 (+ pole) to which a plurality of power-supply terminals 11 with resistances are connected, by energizing for 20 minutes, electrolytic polymerization is performed on each pellet as shown in FIG. 1 (d). The film 9 is formed. As a result, a uniform electropolymerized film 9 can be formed on the pellet 1 as shown in the enlarged sectional views 3 and 6 of the pellet. On the other hand, FIG. 11 shows the state after the electropolymerization of the pellets by the conventional manufacturing method, such as insufficient formation of the electrolytic polymerization film (23b) and excessive formation of the electrolytic polymerization film (23a).
Unlike the above, the electrolytic polymerized film of the embodiment of the present invention can be clearly found to have a uniform shape.

Re-formation step: As described above, the electrolytically polymerized film 14
Reforming is performed on the formed pellets 3 in the same manner as in the conventional manufacturing method. At this time, it was 0.0
A voltage of 15 V is applied for 20 minutes using 1% phosphoric acid.

Step of forming cathode layer: Next, the cathode layer is formed by carrying out the above solid electrolyte layer formation (electropolymerization film) and re-formation, and then forming a graphite paste on the pellets in the same manner as in the conventional manufacturing method. Then, a cathode layer of a conductive material film such as silver paste is formed. The cathode layer connects the solid electrolyte layer and the external terminal (cathode) for mounting, and also has the functions of reducing the connection resistance and relieving the stress when the capacitor is packaged and mounted.

External terminal forming / exterior process: Finally, a metal external terminal is adhered to the above-mentioned pellet after the cathode is formed in the same manner as in the conventional manufacturing method, and further epoxy resin or the like is used for improving moisture resistance and handling property. External packaging is performed to obtain a tantalum solid electrolytic capacitor.

In the present invention, a method of visually observing the appearance state of the electrolytically polymerized film is adopted as the evaluation characteristic. This is a method in which a plurality of pellets that have been subjected to electrolytic polymerization at the same time are visually judged to have a thin portion, a thick portion, or a non-formed portion of the electrolytic polymerization film.

FIG. 6 and FIG. 11 show the appearance states of the pellets obtained by the electropolymerization in which the electrolytic polymerization method of the present invention and the conventional manufacturing method are compared. In this prior art FIG.
Of under-formation 23b or over-formation 23a is observed, while
In FIG. 6 manufactured according to the present invention, it can be seen that the electrolytic polymerized film 9 of the pellets is clearly formed uniformly and the variation between the pellets is small.

The reason why a uniform electrolytically polymerized film can be obtained by the production method of the present invention will be explained with reference to a diagram comparing the correlation schematic diagram 5 of the present invention and the conventional correlation schematic diagram 10. FIG. 5 shows the tip potential of the electropolymerized film with respect to the electropolymerization time when two pellets I and two pellets II are simultaneously fed with electric power through the resistive-feeding terminal 11 to carry out electrolytic polymerization using the production method of the present invention. 3 is a graph showing the correlation between a), electrolytic polymerization current (b), and integrated value of electrolytic polymerization current (c). Further, FIG. 5D is a schematic diagram showing the direction of the electrolytic polymerization current and the position of the tip potential of the electrolytic polymerization layer. The supplementary explanation of the basic part of this figure will be made first. The rate of formation of an electropolymerized film per unit time is proportional to the polymerization current. Further, the polymerization current increases as the polymerization potential increases, so that the formation of the polymerized film becomes faster. Furthermore, as the area where the electropolymerized film is formed increases, the area for energization increases accordingly, so that the current easily flows, and the formation of the electropolymerized film accelerates. The final formation amount of the electrolytically polymerized film is almost proportional to the integrated value of the energization amount. Therefore, in the case of FIG. 5 of the present invention, when the polymerization current of the pellet I shown in FIG.
The polymerization potential shown in 1 decreases to slow the formation of the electrolytic polymerization film,
Conversely, when the polymerization current of the pellet II shown in FIG. 5 (b) decreases, the polymerization potential shown in FIG. 5 (a) rises, so that the formation of the electrolytic polymerization film is accelerated. This operation is such that as the electropolymerization time elapses, the integrated current amount between the pellets becomes almost uniform as shown in FIG. 5 (c), and as a result, as shown in FIG. The formation is uniform.

On the other hand, FIG. 10 shows the case where two pellets I and II are simultaneously subjected to electrolytic polymerization by using the conventional manufacturing method in which power is supplied through the power supply terminal 20 as shown in FIG. 9 of FIG. Is a graph showing the correlation between the tip potential of the electropolymerized film (Fig. 10 (a)), the electropolymerization current (Fig. 10 (b)) and the integrated value of the electropolymerization current (Fig. 10 (c)) with respect to the electropolymerization time. FIG. 10 (d) is a schematic diagram showing the direction of the electrolytic polymerization current and the position of the tip potential of the electrolytic polymerization layer. In this case, the polymerization potential is almost the same for each pellet (Fig. 10).
(a)), the faster the electropolymerized film is formed, the more current will flow (FIG. 10 (b)). As shown in FIG. 10 (c), the integrated current amount of pellet I and pellet II is large. Because of the difference, the state of formation of the electropolymerized film is also greatly different, and as shown in FIG. 11, the electrolytic polymerized film is insufficiently formed 23b, and the electrolytic polymerized film is excessively formed 23a. It will be 23.

Next, a method of manufacturing the solid electrolytic capacitor of the second embodiment of the present invention will be described. In the present invention,
Although manganese dioxide, which is the inorganic semiconductor film 4, is used as a base for electrolytic polymerization, the other operations and effects are the same as those in the first embodiment. The formation of the porous anode body to the formation of the dielectric layer (Ta2O5 layer) is the same as in the first embodiment. The formation of the solid electrolyte layer (formation of the chemically polymerized film) is the same as in the first embodiment, but in the third embodiment, the manganese dioxide layer is formed as the base for electrolytic polymerization. The manganese dioxide layer is manganese nitrate 5
Immerse the pellet in a 0% aqueous solution and put it at 250 ± 50 ° C.
It is formed by heat treatment at the temperature of. The steps of forming the electrolytically polymerized film of the solid electrolyte layer, the re-formation step, the step of forming the cathode layer, and the step of forming / external terminals are the same as those in the first embodiment. In contrast to the conductive polymer chemically polymerized film 7 of the first embodiment, the manganese dioxide layer of the inorganic semiconductor of the second embodiment is somewhat inferior in terms of conductivity. It can be formed uniformly without any difference from the first embodiment.

Next, a method of manufacturing the solid electrolytic capacitor according to the third embodiment of the present invention will be described in detail with reference to FIG. Porous anode body forming process-dielectric layer (T
a2O5 layer), formation of solid electrolyte layer (formation of chemically polymerized film)
Is the same as in the first and second embodiments. In the step of forming the electrolytic polymerized film of the solid electrolyte layer, the electrolytic polymerization solution to be used, the amount of energizing current, the energizing time, etc. are the same as those in the first and second embodiments, but in the present embodiment, as shown in FIG. Several power supply terminals as shown are connected to a third rectangular holder 15 having conductivity at regular intervals to form one block, and one predetermined resistor 12 is connected to each block of the third holder. Then, they are electrically commonized, and are separately arranged in the first solid electrolyte layer 8 of the porous anode body 2 to which the connected power supply terminals are connected, and power is supplied to each block unit of the third holder 15 for electrolysis. By using the block-type resistor-supplied power supply terminal 14 that overlaps, a power supply terminal as shown in FIG. 7 has a plurality of power supply terminals as one block instead of having a resistance in each of the power supply terminals. Block the resistor 12 Performing electrolytic polymerization by feeding for each unit. The subsequent re-forming step, cathode layer forming step, and external terminal forming / exterior step are the same as those in the first and second embodiments. In the block-type resistor-containing power supply terminal 14 of FIG. 7 of the present embodiment, the variation in the formation of the electropolymerized film in one block cannot be suppressed, but the variation in the allowable range of the electropolymerized film formation is suppressed as compared with the conventional manufacturing method. In addition, the structure of the power supply terminal is simple and the production efficiency is improved.

[0042]

As described above, according to the present invention, when the electrolytic polymerized film is formed on the surface of the first solid electrolyte layer made of the conductive polymer film of the inorganic semiconductor film or the chemically polymerized film of the solid electrolytic capacitor, The power supply for forming the electrolytic polymerized film is performed by arranging the power supply terminal having a predetermined resistance or a part of the side of the anode of the power supply wiring circuit other than the power supply terminal with a predetermined resistance so as to be spaced apart from the first solid electrolyte layer. In addition, a plurality of porous anode bodies are connected to a first holder, a plurality of power supply terminals having a predetermined resistance are connected to a second holder having conductivity, and formed, and the connected power supply terminals are connected to a porous body. Since the power supply terminals are not in contact with each other by arranging them separately in the first solid electrolyte layer of the porous anode body and forming an electropolymerized film for each unit of the second holder, the pellet surface (dielectric There is no damage to the body layer). In addition, the cumulative amount of current between pellets is almost uniform, the formation of electrolytic polymerized film between pellets is uniform, the ESR characteristics and variations of solid electrolytic capacitors are small, and the quality can be stabilized. This has the advantageous effect of being able to manufacture a solid electrolytic capacitor that is easy to adopt as a system and has excellent productivity.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating formation of an electrolytically polymerized film in a method for manufacturing a solid electrolytic capacitor according to first and second embodiments of the present invention.

FIG. 2 is an enlarged view of the positional relationship between the power feed terminal with resistance and the pellet of FIG. 1 (c) of the present invention.

FIG. 3 is a partially enlarged view of pellets after molding of the electropolymerized film of FIG. 1 (d) of the present invention.

FIG. 4 is an enlarged view of the rectangular holder of FIG. 1 (a) according to the present invention, in which a power supply terminal with a resistance is joined.

FIG. 5 is a schematic diagram showing the correlation between the tip potential of the electrolytic polymerization film, the electrolytic polymerization current, and the integrated value of the electrolytic polymerization current with respect to the electrolytic polymerization time of the present invention.

FIG. 6 is a state diagram after formation of the electropolymerized film of the present invention.

FIG. 7 is a block-type resistor-containing feed terminal diagram for feeding power via a resistor for each third rectangular holder unit in the method for manufacturing a solid electrolytic capacitor according to the third embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating formation of an electrolytically polymerized film in a conventional method for manufacturing a solid electrolytic capacitor.

FIG. 9 is an enlarged view of the positional relationship between the power supply terminal and the pellet of FIG. 8 (c) in the related art.

FIG. 10 is a schematic diagram showing the correlation between the tip potential of the electrolytic polymerization film, the electrolytic polymerization current, and the integrated value of the electrolytic polymerization current with respect to the conventional electrolytic polymerization time.

FIG. 11 is a state diagram after formation of a conventional electrolytically polymerized film.

FIG. 12 is an explanatory diagram for explaining characteristics of a conventional power supply terminal (Japanese Patent Laid-Open No. 05-283289).

FIG. 13 is an explanatory diagram for explaining the characteristics of a conventional power supply terminal (Japanese Patent Laid-Open No. 2001-102257).

[Explanation of symbols]

1 Anode Lead 2 Porous Anode Body 3 Pellet 4 First Rectangular Holder 5 Dielectric Layer 6 Inorganic Semiconductor Layer (First Solid Electrolyte Layer) 7 Chemical Polymerization Membrane (First Solid Electrolyte Layer) 8 First Solid electrolyte layer (inorganic semiconductor film, chemically polymerized film) 9 Second solid electrolyte layer (electropolymerized film) 10 Second rectangular holder 11 Resistive power feeding terminal 12 Resistor 13 Counter electrode 14 Block type resistive power feeding terminal 15 Third rectangular holder 16 Electrolytic polymerization solution 17 Constant current DC power supply 20 Power supply terminal 21 Fourth rectangular holder 22 Power supply terminal 23 having a contact surface Electrolytic polymerized film (conventional) 24 Soft power supply terminal 25 DC power supply

Claims (5)

[Claims] 1. A sintered body of valve metal powder is used as a porous anode body, and a dielectric layer, a first solid electrolyte layer made of a conductive polymer such as an inorganic semiconductor film or a chemically polymerized film, and electrolytic polymerization are formed on the surface thereof. A second solid electrolyte layer comprising a conductive polymer membrane of the membrane,
In the method for producing a solid electrolytic capacitor, in which a cathode layer is sequentially formed, and then external terminals are connected to the porous anode body and the cathode layer, and a resin coating is applied, a power supply for forming the electrolytic polymerized film is set to a predetermined value. A method for producing a solid electrolytic capacitor, characterized in that a power supply terminal having a resistance is arranged separately from the first solid electrolyte layer. 2. The solid electrolytic capacitor according to claim 1, wherein power supply for forming the electrolytically polymerized film is performed by using a predetermined resistor on a part of the anode side of the power supply wiring circuit other than the power supply terminal. Manufacturing method. 3. The resistance value used for the power supply terminal and a part of the power supply wiring circuit anode side other than the power supply terminal is 10Ω to 10Ω.
It is 00 Ω, Claim 1 or Claim 2 characterized by the above-mentioned.
A method for manufacturing a solid electrolytic capacitor as described in. 4. A plurality of the porous anode bodies are connected to a first holder, and a plurality of power supply terminals having the predetermined resistance are connected to a second holder having conductivity to form the connection. A power supply terminal is separately arranged on the first solid electrolyte layer of the connected porous anode body, and power supply for forming the electropolymerized film is performed for each unit of the second holder. Item 4. A method for manufacturing a solid electrolytic capacitor according to Item 1 or 3. 5. A plurality of the porous anode bodies are connected to a first holder, several power supply terminals are connected to a third holder having conductivity, and one predetermined holder is provided for each third holder. And connecting the connected power supply terminals to the first solid electrolyte layer of the connected porous anode body so as to be spaced apart from each other, and connecting the connected resistance to each of the third holder units. The method for producing a solid electrolytic capacitor according to claim 1 or 3, characterized in that power is supplied to form the electrolytically polymerized film through it.